/*
 * Copyright (c) 2009-2010 David Grant
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package org.jscep.transport.response;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.EnumSet;
import java.util.HashSet;
import java.util.Set;

import org.apache.commons.io.Charsets;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This class handles responses to <code>GetCACaps</code> requests.
 * 
 * @author David Grant
 */
public final class GetCaCapsResponseHandler implements
	ScepResponseHandler<Capabilities> {
    private static final String TEXT_PLAIN = "text/plain";
    private static final Logger LOGGER = LoggerFactory
	    .getLogger(GetCaCapsResponseHandler.class);

    /**
     * {@inheritDoc}
     * 
     * @throws InvalidContentTypeException
     */
    public Capabilities getResponse(byte[] content, String mimeType)
	    throws ContentException {
	if (mimeType == null || !mimeType.startsWith(TEXT_PLAIN)) {
	    LOGGER.warn(
		    "Content-Type mismatch: was '{}', expected 'text/plain'",
		    mimeType);
	}

	final EnumSet<Capability> caps = EnumSet.noneOf(Capability.class);

	if (LOGGER.isDebugEnabled()) {
	    LOGGER.debug("CA capabilities:");
	}
	BufferedReader reader = new BufferedReader(new InputStreamReader(
		new ByteArrayInputStream(content),
		Charset.forName(Charsets.US_ASCII.name())));
	Set<String> caCaps = new HashSet<String>();
	String capability;
	try {
	    while ((capability = reader.readLine()) != null) {
		caCaps.add(capability);
	    }
	} catch (IOException e) {
	    throw new InvalidContentTypeException(e);
	} finally {
	    try {
		reader.close();
	    } catch (IOException e) {
		LOGGER.error("Error closing reader", e);
	    }
	}

	for (Capability enumValue : Capability.values()) {
	    if (caCaps.contains(enumValue.toString())) {
		LOGGER.debug("[\u2713] {}", enumValue.getDescription());
		caps.add(enumValue);
	    } else {
		LOGGER.debug("[\u2717] {}", enumValue.getDescription());
	    }
	}

	return new Capabilities(caps.toArray(new Capability[caps.size()]));
    }
}
